Option Explicit
Dim hola() As String, hi As String
Private Sub Command1_Click()
Dim conta As String
Label1.Caption = Int(Rnd * 10) + 1
Label2.Caption = Int(Rnd * 10) + 1
conta = Int(Rnd * 4) + 1
Label3.Caption = Right(hola(conta), conta)
Timer1.Enabled = True
End Sub

Private Sub Form_Load()

hi = ",+,-,*,/"
hola = Split(hi, ",")

End Sub

Private Sub Timer1_Timer()
Dim result As String
If Label3.Caption = "+" Then
If Not Text1.Text = Label1.Caption + Label2.Caption Then
MsgBox "No lo escribistes a tiempo!"
End If: End If
End Sub